Hitherto, an image forming apparatus has been provided which has an image forming function of printing an image for printing information including characters or figures by an erasable color material and an image erasing function of erasing an image printed on a sheet. The image forming apparatus includes the image forming function and the image erasing function in order to reuse the sheet. The image forming apparatus reads the image printed on the sheet by an image reading unit. The image forming apparatus converts the image read by the image reading unit into electronic data, and stores the electronic data in a storage unit. The image forming apparatus determines whether the image printed on the sheet is erasable based on the stored electronic data, and erases the image in accordance with the determination result.
However, even when the image is printed on the sheet by the image forming function, a user may want to keep the sheet without erasing the image thereon, and hence the sheet having an image printed thereon may not be reused in some cases. Hereinafter, the sheet from which the printed image is erased will be referred to as a reused sheet. Accordingly, there is a case in which reused sheets run out when the user wants to print an image thereon, and hence a new sheet needs to be inevitably used. In other words, there is a problem in that the function of reusing the sheet by the user in the image forming apparatus is not utilized skillfully.